<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body {
            background: pink;
        }
    </style>
</head>

<body>
    <script src="js/utils.js"></script>
    <script>
        var str = '0123456789abcedf';
        var color = '#';
        for (var i = 0; i < 6; i++) {
            // console.log(str[randomNum(0, 15)]);
            color += str[randomNum(0, 15)]
        }
        document.body.style.background = color;
        console.log(color);
    </script>
    </script>
</body>

</html>